STRESZCZENIE

grpck [opcje] [group [ shadow ]]

OPIS

The
grpck
command verifies the integrity of the groups information. It checks that all entries in
/etc/groupand /etc/gshadow
have the proper format and contain valid data. The user is prompted to delete entries that are improperly formatted or which have other uncorrectable errors.

Checks are made to verify that each entry has:

•
the correct number of fields

•
a unique and valid group name

•
a valid group identifier
(/etc/group only)

•
a valid list of members
and administrators

•
a corresponding entry in the
/etc/gshadow
file (respectively
/etc/group
for the
gshadow
checks)

The checks for correct number of fields and unique group name are fatal. If an entry has the wrong number of fields, the user will be prompted to delete the entire line. If the user does not answer affirmatively, all further checks are bypassed. An entry with a duplicated group name is prompted for deletion, but the remaining checks will still be made. All other errors are warnings and the user is encouraged to run the
groupmod
command to correct the error.

The commands which operate on the
/etc/groupand /etc/gshadow files
are not able to alter corrupted or duplicated entries.
grpck
should be used in those circumstances to remove the offending entries.

OPCJE

The
-r
and
-s
options cannot be combined.

The options which apply to the
grpck
command are:

-h, --help

Wyświetlenie komunikatu pomocy i zakończenie działania.

-r, --read-only

Execute the
grpck
command in read-only mode. This causes all questions regarding changes to be answered
no
without user intervention.

-R, --rootCHROOT_DIR

Apply changes in the
CHROOT_DIR
directory and use the configuration files from the
CHROOT_DIR
directory.

-s, --sort

Sort entries in
/etc/groupand /etc/gshadow
by GID.

By default,
grpck
operates on
/etc/groupand /etc/gshadow. The user may select alternate files with the
groupand shadow parameters.

CONFIGURATION

The following configuration variables in
/etc/login.defs
change the behavior of this tool:

MAX_MEMBERS_PER_GROUP (number)

Maximum members per group entry. When the maximum is reached, a new group entry (line) is started in
/etc/group
(with the same name, same password, and same GID).

The default value is 0, meaning that there are no limits in the number of members in a group.

This feature (split group) permits to limit the length of lines in the group file. This is useful to make sure that lines for NIS groups are not larger than 1024 characters.

If you need to enforce such limit, you can use 25.

Note: split groups may not be supported by all tools (even in the Shadow toolsuite). You should not use this variable unless you really need it.